Pending U.S. patent application Ser. No. 700,458, filed on Feb. 11, 1985 and entitled "Method and Apparatus for Effecting Light Energy Transmission", U.S. Pat. No. 4,695,126, discloses an optical fiber connector of biconical type, wherein a plug has a fiber seated therein and defines a frustro-conical outer surface (cone) about the seated fiber. A companion, mating component has a complemental frustro-conical surface interiorly thereof for receiving the plug and supports therein a second fiber or active component for coupling to the first fiber. Typically, the companion component is in the form of a sleeve having frustro-conical interior surfaces extending inwardly from opposite ends thereof for respective coupling of a pair of plugs and their seated fibers to one another.
The plugs of such '458 application connectors seat an end course of a fiber in disposition inclined relative to the plug central axis and the exposed fiber end face is polished at an angle so related to the fiber inclination angle as to render the light energy output axis of the connector coincident with the plug central axis.
Other biconical connectors also commercially available from the assignee hereof are similar in construction to that of the '458 patent, but have the fiber disposed in the plug with the fiber axis coincident with the plug central axis. This type of "standard" biconical connector is a predecessor of the connector of the '458 patent, but remains usable in various applications.
A significant quality control standard for both of the foregoing types of biconical connectors is precise angular disposition of the fiber therein, i.e., inclined or coincident with the plug central axis. Rather substantial rejections of fabricated connectors have heretofore been seen in quality control inspection on the basis of this control standard.
In heretofore known practice for making both types of connectors, the plug has been a molded member throughout, having a bore opening into an end thereof opposite the conical end and formed by a first mandrel upon which the plug was molded in a first molding jacket. This mandrel terminated slightly axially beyond the start of the cone and a second continuation mandrel, in the form of a wire of the diameter of the fiber and its cladding, was secured to the end of the first mandrel. The remote end of the wire was captured by a jewel of a companion molding jacket at a position according with the desired angulation of the fiber in the final assembly, i.e., coincident with the plug central axis in the case of the standard connector and inclined with respect to the plug central axis in the case of the '458 patent connector.
In the described prior practice, the disposition of the wire, and subsequently the fiber inserted in the passage formed by the wire, was highly dependent on both displacement of the wire in response to molding material forces thereon and on the position of the jewel. Both of these factors bear particularly o failure to meet the above quality control standard.